Pressure device



Feb. 9, 1960 J. MERCIER 2,924,244

PRESSURE DEVICE Filed Jan. 22, 1957 m) u m II-T INVENTOR JEA N MERClE/E.

PRESSURE DEVICE Jean Mercier, New York, NY. Application January 22,1957, Serial No. 635,237

5 Claims.. (Cl. 138-60) In pressure accumulators of the type including arigid container having a pair of ports at its respective ends with nitedStates Patent 0 a deformable partition or bladder affixed to one of saidports and separating two fluids such as gas and liquid under pressure,if as the bladder expands to force liquid from the other of such ports,the wall of the bladder adjacent the free end thereof should contact thewall of the container before the portion of the bladder adjacent itsaffixed end, pockets may be formed filled with liquid which would not beexpelled from the container. Thus, the accumulator would be ineflicientin operation as only a portion of the liquid in the container would beutilized.

Where the bladder of a pressure accumulator serves to close the liquidoutlet port when such bladder has expanded in the container tosubstantialy its maximum amount, if such bladder in its inflated butundistended condition is of length substantially equal to that ofthecontainer, the liquid outlet port may be closed before substantially allof the liquid is expelled. If the bladder is considerably shorter thanthe container and upon expansion of the bladder, as fluid is forced fromthe container, when the major portion "of the bladder wall engages thewall of the container, the free end of the bladder should beconsiderably spaced from the liquid outlet port, such free end wouldhave to stretch excessively to reach the liquid port to close thelatter, thereby subjecting the bladder to high stress with likelihood ofrupture.

It is accordingly among the objects of the invention to provide apressure accumulator of relatively low cost, which may readily befabricated and which will function without likelihood of breakdown orrupture of the deformable bladder therein and with assurance thatsubstantially all of the liquid will be expelled from the container.

Another object is to provide a bladder for a pressure accumulator of theabove type which may readily be formed and which will provide forsubstantially complete expulsion of liquid from the accumulatorcontainer without likelihood of rupture of such bladder.

According to the invention, a partition or bladder is positioned in arigid container to separate two fluids therein and is afllxed in thecontainer in such manner that the bladder defines two chambers for suchfluids. The bladder is of greatest diameter adjacent the ailixed portionthereof and the slide wall of the bladder is substantially concave onits outer surface between the portion of great est diameter and the freeend of the bladder with all portions of the outer surface of the bladderbetween the greatest diameter portion and the free end being of diameterless than or substantially equal to a pressure port1on.

This application is a continuation-in-part of copending applicationSerial No. 407,947, filed now Patent No. 2,786,488, March 26, 1957.

In the acompanying drawings in which are shown one:

or more of various possible embodiments of the several features of theinvention,

Ice

Fig. 1 is a longitudinal sectional view of a pressure accumulatoraccording to one embodiment of the invention, and

Fig. 2 is a view similar to Fig. 1 of another embodiment of theinvention.

Referring now to Fig. l of the drawings, the pressure accumulatordesirably comprises a container or pressure vessel 11, preferably ofstrong, rigid material such as steel, cast aluminum or the like, capableof withstanding high pressure and having a gas inlet port 12 and aliquid port 13 therein preferably opposed to each other. The container11 may be spherical or cylindro-spherical as shown and has a partitiontherein between the gas and liquid ports, said partition illustrativelybeing a collapsible and expansible bladder 14, desirably of resilientmaterial such as rubber or synthetic plastic of like physicalcharacteristics, which in distended but substantially unstretchedcondition is smaller than the cavity of the container 11 and has itslongitudinal axis aligned with the ports 12 and 13.

As shown in Fig. l, the bladder which is of length illustratively noless than three times its maximum dilower end 22 of the cylindricalportion 19 equal to a February 3, 1954,

ameter, has a rounded end 15 conforming to the curvatureof the end 16 ofthe container 11 adjacent port 12 and is substantially in engagementtherewith to the maximum diameter portion 17 of the bladder, and aportion 18 of the side wall of the bladder tapers inwardly from themaximum diameter portion 17 of said bladder. Thus the tapered portion 18of the bladder is in the form of a frustum. The portion 19 of thebladder between the tapered portion 18 and the free end 21 thereof issubstantially cylindrical in cross section extending substantiallyparallel to the wall of the container 11.

To minimize fatigue at the free end 21 of the bladder,

such free end 21 has an outer width as at aa at the distance D, and thecurvature of each of the side ends '23 of the bladder from theextremities of the line a-a is a portion of the curve of a circle havinga radius AD taken along line a-a. The lower end 21 of the bladder has acurvature formed by a circle having a radius D with its axis along thelongitudinal axis of the bladder.

As shown in Fig. 1, the thickness of the tapered portion 18 of thebladder wall gradually decreases from the larger'diameter portion 17thereof to the upper end 25 of the cylindrical portion 19 and thethickness of the cylindricalportion 19 gradually increases from itsupper end 25 to its lower end 22. p p

The bladder 14 is rigidly affixed in the container 11 preferably bymeans of a fitting 31, which desirably has a substantially cylindricalstem portion 32 with a base disk presenting an outstanding lateralflange 33 at one end thereof, which desirably has an annular groove 34in its upperface 35 in which may be positioned the thickened rim 36about the mouth of the bladder 14. Thus, when the parts are assembled asshown in Fig. 1, the bladder may be securely clamped in place by meansof a nut 38 screwed upon the protruding threaded stem of the fitting, anannular shoulder 39 adjacent the root end of the stem abutting againstthe rim of the gas inlet port 12 to prevent cutting of the rim 36 of thebladder by excessive tightening of the nut.

- Although the outlet port 13 of the accumulator could be controlled inany suitable manner, in the embodiment herein shown, it is preferred touse the general construction shown in United States Patent No.2,469,171, dated May 3,1949, by the use of which an outlet closureassembly 41 aflixed in said port 13 may be removed with out likelihoodof injury to the mechanic. As shown in Fig. 1, this. assembly desirablycomprises a housing 42,

preferably a tubular member which desirably has an,

outl t 13.

3 of outer diameter less than thatof port 13. A locking. member 44,illustratively a ring of greater outer diameter than said port 13 anddeformable to permit its insertion thereinto, encompasses saidtubularmernber and is seated on the rim 45 of port 1-3, the innerdiameter of said. ring 44 being less than the outer diameter of shoulder43 so that said shoulder may seat on' said-rim. Encompassing saidtubular member and in juxtaposition withsaid port 13 is a rubber gasket46 which serves el iectiv'ely' to prevent leakage between the wall ofporlt' lfil'andxthe outer wall of tubular member 42 when a nut 47 isscrewed on the externally threaded portionl48 :offsaid tubular member32, a i r I Desirably positioned in said tubular member 42 is a poppetvalve comprising ayalve head Sl adaptedto seat on the beveled mouth 52:of't'ubular member 42 and having a stem 53 preferably formed integraltherewith.

, tion 17. The angle between the bladder wall and the container at eachinstant of contact desirably is substantially equal, illustrativelyinthe order of five degrees, which is suflicient to provide sufficientdistance not to trap liquid and the minimum angle for a long bladder ofthe dimensions above set forth. Thus, the portion of y the bladderadjacent the point of contact thereof with Stem 53 is slidablylrnountedin'beaiingppening :54; .de-.

sirably in a disk 56 mounted inrthe bone of tubularmember 42, said diskhaving a'plui'alityof openings. 58. therethrough to permit the passageof fluid, said yalvehead being'norrnally retained, in open position bymeans of a coil spring 59 encompassing stem 53' between head 51 and disk56. As the construction and operation of said outlet closure assemblyper se forms no part'j of thisin ventiou it will not'be furtherdescribed.

The embodiment shown in Fig. 2 is substantially identical to that shownin Fig. 1 except for the construction of the bladder and correspondingparts have the same reference numerals primed.

As shown in Fig. 2, the bladder 14 which:has a substantially constantwall thickness, has a rounded end 15' conforming to the curvature of theend 16. of .the container'll' adjacent port 12 and is substantially inengagement therewith to the maximum diameter portion 17 of the bladder'14. v

The portion 61 of the side wall of the bladder between its maximumdiameter portion 17. and its freeend 21' is substantially conical incro'sssection, being concave on its outer surface with all portions ofsaid side wall 61 between the greatest diameter portion 17 and the freeend 21' being of diameter less than ,orsubstantially equal to a previousportion.

With the construction shown, when -a-valve (not shown) controlling theliquid outlet port :13; for example, is opened, the bladder will expandand elongate to force liquid fromsuch outlet. i

To avoid trapping of liquid between the bladder andthe container, thebladder when expanding must progresr.

siVClY contact the container wall from the maxiniumdiameter portionthereof to near the liquid port so that substantially all of the oil inthe container will :be forced fromsaid port.

In addition, with a long bladder, ,i.e.,-when the length of bladderis atleast three times its, maximum diameter, it :is essential that the lowerend of the bladder be sufiicientlyclose to the lower end of thecontainer so..that upon final expansioniof the bladder to closethe'xliquid port, the free end of the bladder will'be sufficiently,close to the lower end of the container to avoid excessive stretching ofthe bladdenwhich rnightjcause rupture thereof. a

These results are accomplishedby the constructions above described.Thus,'as the jroundedend ;1 5"(Fig. 1.) of the bladder conforms to theshape of theend 16 of the container 11 and is substantially against thelatter, when the bladder starts, to expand the end 15 will immediatelypress against end 16 so (that rubb'ing is avoided n a l au d lLb pped-As the region .of the "bladdertadjacent'the maximum the containerneveris parallel to the container.

,When the thinnestregion 25 of the bladder has engagedythe wall of thecontainer, as the portion 19 of the bladder is substantially parallel tothe wall of the container. and is of progressively increasing thickness,as it is sufficiently spaced from the container-.1 wall, the portion 19will also progressively engage the wall of the con-.

tainer at asubstantially constant angle at the' moment of contact' from.the thinnest region 259to the region 22 to preclude entrapment of liquid.

As the wall thickness of the portion 18 of the bladder V progressivelydecreases from the maximumdiameter portion 17 to the region25, eachsucceeding region of such portion 18 will increase inlengthas set forthin co-pending application Serial No; 407,9;47, filed February 3, 1954,at a greaterrate, than the. previous portion. Consequently, upon,expansion and, elongation of the:bladder, the portion 19 of thebladderwill move downwardly sufficiently so that th lcwerp rtioa 22'.ofrthe bladder will only have to stretch a relatively small 'amountbefore 1 the end 21 engagessthe valvehead 5.1 to close the outlet a en hladder tall ex anded;

PQl' h by avp i ss ress on suah lower p r i n wh c might causerupturejof'the, bladder andfailure of the unit.

Thns, where the bladder is-relatively long, i.e., of length er an th eeme ts, ma iinum diameter and it it was coniealin ctoss sectionalong itsentire length, the

a great distancefrcrn the endofthe container that rupwe i ht o cur! hiss predu edwiththe con truct n prs s cssribcdt I In the embodiment shownin Fig. 2, as the wall portion 6 9 the h aslderis ubs ant allrrcansevapp oac b n t. eachin Par lel ela ion to h c n ain r. Pro ressive e aemen f thcbladder with the container al t a b.

pre lude I i In addition, as the lower end of the bladder will not sl sivs rnaccd t am he cn ai erwal ven w a long blagldensuehlower end willnot havc to, stretch ce e y assa a i en ag me t, with the container Withthe constructions above described, entrapment of liquid; due to.theforrnation of pockets is substantially p e de i h. h resultant i h efici ncy. i the p tion f t vawlatc e Bathe tiiizeti nac u s tially al Ofthe i uid. in e wntainer-w Furthermore, as the, lOWBl' end of the.bladder will.

berrelatively. c loseto the lower portion of the side wall of, thecontainer when the bladder has expanded, the

diameter portion 17 is closestto the wall of the' conportion of thebladder at itslower end will only have to stretch a relatively smallamount before the outlet port. is sealed thereby avoiding stress on suchlower portion which might cause rupture of the bladder and failureof theunit. t l

As a t ang scal e mad t e abo e sawmtions, and many apparentl widelditrferenternbodiments Q is ir v i ia suldb made withwtds art ns from hescars ,o the {claims itlis titended that l we c n:

tained in the above description or shown; in the agcont;

. t a ly canstantan lc at the moment at sst qt w ll es ur- "thiientrapment of liquid panying drawings shall be interpreted asillustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A bladder for a pressure accumulator comprising an elongated hollowmember of resilient deformable material having a port at one end, saidbladder being substantially conical in cross section adjacent the portend thereof and substantially cylindrical in cross section from theconical portion toward the free end of the bladder, said bladder beingof maximum diameter at the extremity of the conical portion remote fromthe cylindrical portion.

2. The combination set forth in claim 1 in which the conical portion ofthe bladder 'wall is of progressively decreasing thickness and thecylindrical portion of the bladder wall is of progressively increasingthickness toward the free end of the bladder.

3. A bladder -for a pressure accumulator comprising an elongated hollowmember of resilient deformable material having a port at one end, saidbladder having the outer surface of the side wall thereof concave atleast along a portion of the length of the bladder and in the length ofthe bladder is at least three times its maximum diameter.

form of a curve which continuously approaches nearer to 25 thelongitudinal axis of the bladder but never reaches such longitudinalaxis, said concave portion being of maximum diameter near the port endof the bladder.

4. The combination set forth in claim 3 in which the 5. A pressureaccumulator comprising a rigid elongated hollow substantiallycylindrical container having apair of axially aligned ports, anelongated hollow bladder of resilient deformable material in saidcontainer having a port at one end affixed to one of the containerports, said bladder having the outer surface of the side wall thereofconcave at least along a portion of the length of the bladder and in theform of a curve which continuously approaches nearer to the longitudinalaxis of the bladder but never reaches such longitudinal axis, saidconcave portion being of maximum diameter near the port end of thebladder, said bladder when in substantially undistended condition havingits longitudinal axis aligned with both of the ports of said containerand having its side wall spaced from the container wall substantiallythe major portion of the length of said bladder.

References Cited in the file of this patent UNITED STATES PATENTS2,469,171 Mercier et al May 3, 1949 2,604,118 Greer July 22, 19522,773,511 Mercier Dec. 11, 1956 FOREIGN PATENTS 710,746 Great BritainJune lti, 1954

